Color photography



Aug. 13, 1929.

w. R. WHITEHORNE 1,724,445

COLOR PHOTOGRAPHY Filed Aug. 24, 1925 2 Sheets-Sheet. l

COLC RED RED COLORED YELLO W COLORED BLUE mm! X! low a: Green fled NYGHOW Blue g- 13, 1929- w. R. WHITEHORNE 1,724,445

COLOR PHOTOGRAPHY Filed Aug. 24, 1925 2 Sheets-Sheet 2 sown YELLOW COLODBLUE COLORED RED and involves a method Patent Aug. 1, i929.

Application filed August 24, 1925. Serial No. 58 ,000.

to color hotography by which such photographs can be taken and preparedwith a minimum of time and a maximum of accuracy in color reproduction.

My invention may be differentiated from former methods first by thegeneral statement that it does not depend upon the use of screens o rfilters. The advantage of this in the saving of time and thesimplification of My invention relates apparatus is obvious. Myinvention is perhaps most particularly characterized by my use of one ormore plates, films or other sensitized media which are particularlyinsensitive with regard to certain parts of the spectrum. The matter ofdifferentiated sensitiveness, generally speaking, is not new, but in myinvention this matter of a special or characteristic insensitiveness ismade "to play a somewhat difierent part than has heretofore beenaccomplished or attempted.

I have found that lat-es sensitized in certain manners, as will behereinafter discussed, may be thereby rendered relatively insensitive tocertain colors or wave lengths so as to show a very marked orcharacteris tic band as readily ap rs from the spectrogram. Such platesive 11 developed for photography of special subjects, butusually withparticular reference to their photographic power in general regions.This is usually obtained at the-expense of lack of sensitiveness incertain other regions, which lack of sensitivenes's whileunde(s1i1il'1abl e, lilas not bgelan a serious defect for or a oto a 'coses.

In a ofdance wi th my i ngention I utilize this very incident ofinsensitiveness as a means of obtaining the desired color effect, thatis to say, by deliberately employing a plate which is quite definitelyinsensitive to a certain color I am able by my method to intensify thatvery 'color in my ultimate picture to which a selectal plate iscomparatively blind.

As is well known to those shlled in this art, there is great dificultyin obtaining aings to illustrate certain characteristic media and thosesteps by which such photographs can be produced. To these I shall makereference by the usual characters similarly applied throughout. In thedrawings I have selected as an object to be photographed what may beconsidered as a childs all or plaque striped in difierent colors. Whilethis does not involve the depiction of intermediate colors or shadings,it is believed that the production of these intermediate effects will'beseen by those skilled in the art to follow naturally according to theprinciples disclosed. In these draw s: a

Fig. 1 is intended to represent an object such as a disk or ball s'tripdvertically in difierent colors. Figs. 2 and 3 atives thereof. Fig 4 is adiagrammatic illustration of a composite or doubling of these negatives.

Figs. 2", 3 and 4 indicate s tograms showing the light intensities ofthis plates. Figs. 5, 6 and 7 indicate prints from the plates of Figs.2, 3 and 4.

Figs. 8, 9 and 10 represent these prints as Q tonw or dyed.

Fig. 11 indicates the transmitted color valuels of these threeprintswhen superimpose V I Figs. 12, 13 and 14 represent a pair ofnegatives and their composite dia m corresponding to Figs. 3 and 4, butinvolving modified procedure.-

Figs. 12, 13 and 14 indicate a spectrogram of the light intensities ofthe plates, dicated in the pr Figs. 12, 13 and 14.

Figs. 15,16 and 21 represent prints there, from corresponding to Figs.5, 6 and 7.

Fig. 17 indicates a print from the plate. of Fig. 21, giving itsreversal.

Figs. 19 20 and 18 represent the'colored prints of Figs. 15, 16 and 17,and

Fig. 22 represents the transmitted lightvalues of the sluiperimposedcolored prints.

The object selected for convenience of illustration and while its colorsare handed rather than otherwise distributed, as in most pictures orscenes, it will be unde that the princi-- ples involved are the same.

As suggested earlier herein, m method offers unusual possibilities forection in shown in Fig. 1 is merely be then made in the reproduction ofpredominant or important colors in any selected subject or view to bephotographed. While therefore the object X shown in Fig. 1, does notcall for any particular intermediate color treatment, we may assume thatit is desired to favor a green color as would be the case if a landscapewas taken in which trees and plants predominate.

In order therefore to favor the green or its important component yellow,I employ a plate B which has been bathed or otherwise prepared with asolution which renders it substantially insensitive to the green yellowregion. This may be readily seen in a spectrogram as indicated in Fig. 3which shows a broad bright band through this region.

With this plate I use a plate A, which may be an orthochromatic plate,which shows a considerably differentiated spectrum band as indicated inFig. 2. These plates may be exposed in any desired manner. Veryconveniently they may be assembled in tandem in a pack or loaded into aplate holder in superlmposed position and the picture may the usualmanner in an ordinary camera at substantially the same speeds thatordinary pictures would be taken.

While I mention this superimposed exposure of the plates as convenientin the practice which I have followed as it assures registry of theprints, I would explain that any filtrative effect, such as has beenheretofore stressed in certain processes depending upon filtration, maybe relatively ignored, for the purposes of the present application, asmy invention is not dependent upon such, an action and as such an actionis wholly incidental to the more important factors which I will nowdescribe.

While the two negatives A and B heretofore described are veryconsiderably differentiated chromatically, and in one phase of myinvention capable of use in two color work where it is desired to getmore faithful reproduction of the natural colors a third color s stem ispreferable as is general in color p otography.

In the practice of m fore, instead of attempting invention, thereto takea third negative at the time the lpictur is snapped,

I take my two negatives and B and superimpose them as diagrammaticallyillustrated in Fig. 4. In this figure it will be seen that the densitiesof the negatives or the indicated intensities in the s ctrum asindicated by the lighter portion in Fig. 4, is very much narrower and aprint from the superimposed negatives A and B gives a print or positive1n which the yellow is very strongly accentuated as indicated in Fig. 7.

If new prints be taken from negatives A and B, the prints will appearsubstantially as shown in Figs. 5 and 6, in which the stripes areconsiderably differentiated.

These prints 5, 6 and 7 may be considered as lantern slide prints or maybe of any other I then dye or tone the prints A B (AB) as for example,red, blue and yellow, respectively, as indicated in, Figs. 8, 9 and 10.

If now these plates or members indicated in their dyed condition as A Band (AB) are superimposed the transmitted light Will make the objectphotographed come out sub stantially in its original color as I haveattempted to indicate in Fig. 11. In that figure it will be seen thatthe black stripe of the ball having comeout strong in each of the printsshows the combined red and yellow very much darkened by the blue, sothat the effect is a dark brown which is supposed black in value. Thegreen stripe is'made up of the superimposed blue and yellow of prints Band (AB) which by reason of their careful selection may be made to showthe desired green with very great faithfulmaterial adapted for thepurpose.

ness. The red stripe is clearly presented by 1 the red of plateA Theyellow is strongly presented by the plate (AB) 2 and the blue by theplate B It Wlll be particularly noted that the yellow of the plate (AB)2 comes from the overlap of the spectrum values ofplates A and B,

so that the ultimate slide member comes out which was the very color towhich the sensitized plate B was blind.

The plate selected for representation as plate B and as indicated by thespectrum diagram 3 happens to be what is known as a .pinorthol, whichhappens to give the particular band shown in the spectrum. In certaincircumstances where some colors other than green appear prominently, itmight be desired to furnish plates of different characteristics for thepurpose of favoring thosestantially insensitive to the color desired, by

taking a print from the combined negative so .with a very particulardefinition ofyellow Ill as to secure a narrowing of the bright band inthe combined spectrum.

In the procedure which I will now describe I will discuss a method bywhich I take two plates which includes one which is considerablysensitive to the color desired, but insensitiveto some other color. Ithen proceed to take my composite negatives as indicated in Fig. 14, buttake from them a print which reverses the values and using this print asindicated in Fig. 17 as a negative, produce an ultimate print as in Fig.18, which I use for the color to be less favored, as will be seen by thefollowing.

If the plate A indicated in Fig. 12 be an ordinary plate, dyed forexample with pinacyanol blue, its spectrogram (indicated in Fig. 12)will be dark in the red generally and dark in'a narrow band of the bluegreen. As indicated in Fig. 13, the spectrogram of plate C while havinga bright band in the red is sharply cut off between the blue and thered. In the composite therefore the print (AC) will be light in the redand dark in the blue, while the print (AC) 2 (Fig. 17) from (AC) (Fig.21) will be dark in the red and light in the blue.

The print A shown in Fig. 18 is then dyed or toned red; the print C(Fig. 19) is dyed or toned blue; and the print (AG) (Fig. 20) is dyed ortoned yellow.

Transmitted light of these combined plates will show a very good red anda somewhat yellowish green, or in other words, will express to advantagethe red-orange and yellows at the expense of the green.

It will be seen from these two examples that my method involves peculiarpossibilities in its utilization of chromatic difierences in plateswithout screens, first, by a recognition of true possibilities of suchdifierentiation, and second, by what might be called an additivesubtraction as in the case of the using of a composite plate, and third,by the additional step of reversal of the print from the compositenegative to supply the third color.

As additional instances of my process, plates, or films may be made upas follows:

For a two color picture I preferably use what we may call a pinacyanolblue plate as heretofore referred to, and an ordinary or ortho chromaticplate. These give an excellent separation of the red from the blue andthe result is very-satisfactory.

For a three color result from two plates, as hereinbefore described, Iprovide an erythrosine dyed plate and a pinacyanol dyed or a pinacyanolblue dyed plate. The latter is preferable for pictures in which there isa considerable amount of yellow. The erythrosine plate separates theyellow from the red better than the polychrome plate and the two platesof this character may be combined to produce a third plate as beforedescribed. v

Where exposure can be made using three plates or surfaces in theoriginal exposure, I find very satisfactory results come from the use ofan erythrosine plate, a pinacyanol blue plate and a pinacyanol. Wherepictures are taken in succession I substitute a pinorthol II for thepinacyanol. Where the plates are exposed in tandem it does not or othercolor photographs from such negatives is simple and may be done byordinary contact'printing and by ordinary methods of toning or dyeing.All such modifications and variantsare to be understood as within thescope of my invention which I have defined in the following claims.

What. I therefore claim and desire to secure by Letters Patent is: I

1. In sensitized media for color photography, a pair of sensitizedsurfaces having a common color insensitiveness in one region of thespectrum and a different color insensitiveness in another part of thespectrum.

2. In a systemof color photography the exposure of plural sensitizedsurfaces, one of said surfaces having a predetermined insensitivenessto. a desired group of wave lengths, in reversing the negative so formedand printing therefrom to secure a colorable member or color photograph.

3. In a system of color photography, the production of a pair of photonegatives from sensitized media having common color insensitiveness inone region of the spectrum and a difi'erent color insensitiveness inanother part, and in preparing a print combining the efi'ect of thejoint insensitiveness of the two negatives first mentioned.

4. In a system of color photography, the production of a pair ofphotonegatives including one of characteristic color insensitiveness, inproducing a print fromthe composite negatives, and in preparing coloredprints from the individual negatives and from the composite print.-

5. In a system of color photography, the production of a pair of photonegatives from sensitized media having common color insensitiveness inone region of the spectrum and a different color insensitiveness inanother part, and in preparing a print combining the effect of the jointinsensitiveness of the two negatives first. mentioned, and in takingcolored prints from the said first mentioned negative and from thecomposite print.

6. In a system of color photography, the production of a pair of photonegatives including one of a redetermined color insensitiveness in proucing a third-print from the composite negatives," and in preparingcolored prints from the individual negatives and from the compositeprint as a negative.

7. In a system of color photography, the

production of a pair of photo negatives each therefrom a thirdchromatically diflerenti- 15 having a common color deficiency in oneated member in color supplementing relation part of the spectrum andeach having a difthereto.

ferent color deficiency in another part, and 9. In a multi-colorphotographic process 5 in preparing diflerently colored prints therethemaking of two chromatically difierentifrom in predeterminedsupplementing chro: ated negatives, and in producing therefrom maticbalance. three or more chromatically cooperative 8.In a multi-c'olorphotographic rocess color plates for assembly.

the making of two chromatically difi erenti- In testimony whereof Iaflix my signature.

:0 ated exposure members, and in producing WILLIAM R. WHITEHORNE.

